I have seen a couple of really good series from Czechia in the past year or two and this follows the trend. I really liked it. However, I'm going to make a caveat that this might not be for everyone. Those of a staid disposition might be put off by the use of the camera - in situations where there are conversations between people, only one camera is used and pans from one person to the other rapidly and jerkily. It does this during other scenes too. There's also the usage of several disconnected shots of characters walking that jumpily show their progress.
There's also a voiceover from one of the main characters. I cordially dislike voiceovers but this is done in a completely original way, the character David breaking off from the action and speaking directly to the camera with a different lighting to the previous scene which we shall return to after his soliloquy.
Then the story itself. There are plots within plots and it's easy to get confused and surprised at the twists and turns of the story. I had guessed at who did the original murder, but the scriptwriters cleverly made me doubt my own faculties. We also realise, in tragic circumstances, that the "Mr Big" has a boss of his own in the final episode. The end of the episode holds a final surprise and is a shocker confirming the identity of the perp of the first murder.
Characterisation is deftly handled. One can believe that these people exist in the real world. They might not be attractive, in many respects, but they are true to life.
About 5% of the series has Vietnamese dialogue. Unfortunately, the version I watched had Czech subtitled into English but Vietnamese subbed into Czech. There was, however, just one part where I really wondered what was going on. In the rest, it was followable by interpreting gestures, speech patterns, tone and pitch as well as the very few words in Czech that I could understand on the screen.
I doubt that there could be a second season with similar themes but there is scope for it with some different characters. But this was perfect as a stand alone series. I'd watch another effort without a hesitation, but would be apprehensive that they might not achieve what they did here.